Chevelle Camaro Nova Exhaust Heat Riser Small Block SB$51.0eBay Nova - Chevelle - Camaro - Monte Carlo Exhaust Heat Riser - Small Block Description Brand New Reproduction Small Block Exhaust Heat Riser Attaches between the exhaust manifold and the head pipe When the engine is cold, this valve will close to restrict exhaust gasses and speed the heating of the exhaust manifold Use one per car Fits the following Small Block models: 1964 - 1969 Chevelle - El ... More